Signal tower

Due to constant raids from the Servants of the blood gods, Masked of Dantea started to employ a signalization system all over the Whitestone Island

General layout:

The rather simple stone tower starts off as a wide circular structure, where the 4 soldiers operating the tower reside. It then drastically starts to get slimmer, as a ladder leads 50 meters up. The top of the tower is of a brazier-like design, with a short wall dividing the edges from a large pit full of wood and dried plant matter.

Rooms:

Barracks:

Located at the bottom of the tower, this large room contains beds for the 4 soldiers, a small kitchen and a large table. The soldiers are free to decorate and change everything as they please, at their own expense. Soldiers usually bring things like cards to pass the time.

Brazier:

The top of the tower is built like a brazier, the center filled with wood and dried plant matter. When lit, it can be seen from far away and last more than 5 hours. The soldiers put a roof made out of leaves tightly tangled together when it rains, to ensure it stays dry for emergencies.
The fire is surrounded by a short wall, dividing it from the edges of the tower, so soldiers can stay up there while the fire is burning.

Additional information:

Hidden rooms/ entrances

From the barracks, part of the wooden floor can be opened, which leas to a small basement of sort. It holds supplies for up to a week and can act as a hiding place for the soldiers in case of an emergency.

Defenses:

The only defenses are the 4 soldiers, making the signal tower easy to capture and let out fake signals.

Cost to build:

(Time, money, resources, workers, etc.)

Signal types:

While the towers were made to signal incoming raids to the surrounding settlements, they started to have other signaling purposes. Different substances are used to color the fire for at least a short while, to signal all sorts of things.
Default: The regular fire is used to signal raids or other attacks on the local settlements, so the army can mobilize and anyone nearby can evacuate.
Green: Green fire signalizes a disease outbreak. It is advised for everyone to stay within their settlement for some time, before the outbreak dies down.
Blue: Blue fire signalizes false alarm, in a case of a mistake.
Red: A lockdown. Everyone is to stay in their homes until further notice is given. This signal is used in cases of a possible event where people would come to harm outside. It has yet to find a use.
Black: Black some is used in the case the signal tower is captured by enemies. It lets everyone know that the future signals are false.
Purple: Purple was never used, and that's for a good reason. It is used to signalize a catastrophic event, such as the crystal dragon attacking. Because of the threat's level, no soldiers or defenses are prepared for it. The best thing to do is to run away an hide, hoping to survive till the end.

Type

Tower, Guard